The invention pertains to the field of slip form molds, or screeds and particularly to means for incorporating stationary objects into the slip form molded formation.
Elongated concrete formations, such as walls, highway barrier walls, and the like can be economically formed by continuously moving slip forms commonly known as screeds. Such apparatus includes an open ended form having a hopper at the forward end receiving concrete. As the screed, which is mounted upon a movable vehicle or carriage, moves, the concrete within the hopper enters the screed and is formed into the desired shape. Vibrators and compacting apparatus is utilized within the slip form to compress and settle the concrete, and this vibration, in conjunction with a low water-to-cement ratio, permits a sufficiently "stiff" formation to be molded capable of retaining the desired shape upon withdrawal of the screed.
In my U.S. Pat. No. 3,792,133 I disclose apparatus of the aforementioned type used in the construction of highway barrier wall.
When constructing concrete structures by slip forming, particularly those of significant height, such as above two feet, it is often desirable to introduce reinforcement rod or mesh, electrical connections, special supporting structure, and other stationary elements into the concrete formation, and when constructing highway barrier wall, it is common to incorporate such elements into the wall as well as to mount lamps upon the barrier wall, and such lamps require electrical conduits and bases to be incorporated into the wall during forming.
While it is known to provide slip forms, and their hoppers, with means for introducing reinforcing into the slip form, and removable panels have been used in slip form hoppers as shown in my U.S. Pat. No. 3,792,133, it has heretofore not been possible to readily introduce stationary objects into the screed without losing a significant amount of concrete through the hopper entrance opening, and, in the past, many problems have been encountered in endeavoring to incorporate stationary objects into slip formed walls.